import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        System.out.print("请输入第一个边长：");
        double a = scanner.nextDouble();
        System.out.print("请输入第二个边长：");
        double b = scanner.nextDouble();
        System.out.print("请输入第三个边长：");
        double c = scanner.nextDouble();

        if (canFormTriangle(a, b, c)) {
            System.out.println("这三个数可以构成一个三角形。");
        } else {
            System.out.println("这三个数不能构成一个三角形。");
        }

        scanner.close();
    }
    private static boolean canFormTriangle(double a, double b, double c) {
        return (a + b > c) && (a + c > b) && (b + c > a);
    }
}